Machines in the Mac Business Unit were compromised.

Facebook, Twitter, Apple, and now Microsoft. Redmond has announced that it too has found compromised computers on its network.

A brief statement on its Security Response Center blog states that a small number of computers—with machines in the Mac Business Unit mentioned explicitly—were compromised using techniques "similar" to those documented by other victims, implying, but not outright stating, that the attack vector was a Java exploit placed on a popular iOS development site.

Microsoft says that no customer data was exposed, and it is continuing to investigate.